This proposal involves psychological factors, such as stress and personality, in the etiology of hypertension, especially with respect to familial trends and sex differences. The study is designed to evaluate similarity of cardiovascular measures within families under two kinds of mild stress (an unsignaled reaction time task with monetary incentives, and an oral spelling quiz) and two resting conditions (a short period immediately preceding the stress situations, and a rest period on a day when no stress is scheduled). Previous research has shown that young adult males and younger adolescents of mixed sexes are more responsive to certain kinds of stress in heart rate and systolic but not diastolic blood pressure, if they have a parent with hypertension than if they are without a family history of cardiovascular disease. Since hypertension shows strong familial concordance as each generation ages, it is expected that the stress reactivity which is related to parental hypertension may itself prove to be a predictor of eventual development of high blood pressure. Resting differences between offspring of hypertensive and normotensive parents are typically smaller and less predictive. This study focuses on two additional age groups (7 to 10-year-old preadolescents and their 30 to 40-year-old parents) and assesses cardiovascular reactivity in two consecutive generations rather than presence/absence of hypertension in one; however, data on presence of hypertension in a third generation (the grandparents) will also be sought. In addition, sex differences and certain personality factors which may modify cardiovascular reactivity will be evaluated. The possible long-term contribution involve both cardiovascular psychophysiology and assessment in cardiovascular disorders; increased knowledge of familial concordance, the role of stress and personality in the etiology of hypertension, and the possibility of earlier identification of high risk individuals are desirable outcomes of this research.